The initialization takes a chardev backed by a unix domain socket. It should implement qemu_fe_set_msgfds in order to be able to pass file descriptors to the remote process. Each ioctl request of vhost-kernel has a vhost-user message equivalent, which is sent over the control socket. The general approach is to copy the data from the supplied argument pointer to a designated field in the message. If a file descriptor is to be passed it will be placed in the fds array for inclusion in the sendmsg control header. VHOST_SET_MEM_TABLE ignores the supplied vhost_memory structure and scans the global ram_list for ram blocks with a valid fd field set. This would be set when the '-object memory-file' option with share=on property is used. Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com> Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
/*
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* vhost-backend
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*
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* Copyright (c) 2013 Virtual Open Systems Sarl.
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*
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*/
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#include "hw/virtio/vhost.h"
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#include "hw/virtio/vhost-backend.h"
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#include "qemu/error-report.h"
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#include <sys/ioctl.h>
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extern const VhostOps user_ops;
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static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
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void *arg)
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{
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int fd = (uintptr_t) dev->opaque;
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assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
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return ioctl(fd, request, arg);
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}
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static int vhost_kernel_init(struct vhost_dev *dev, void *opaque)
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{
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assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
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dev->opaque = opaque;
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return 0;
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}
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static int vhost_kernel_cleanup(struct vhost_dev *dev)
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{
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int fd = (uintptr_t) dev->opaque;
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assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
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return close(fd);
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}
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static const VhostOps kernel_ops = {
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.backend_type = VHOST_BACKEND_TYPE_KERNEL,
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.vhost_call = vhost_kernel_call,
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.vhost_backend_init = vhost_kernel_init,
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.vhost_backend_cleanup = vhost_kernel_cleanup
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};
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int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
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{
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int r = 0;
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switch (backend_type) {
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case VHOST_BACKEND_TYPE_KERNEL:
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dev->vhost_ops = &kernel_ops;
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break;
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case VHOST_BACKEND_TYPE_USER:
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dev->vhost_ops = &user_ops;
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break;
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default:
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error_report("Unknown vhost backend type\n");
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r = -1;
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}
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return r;
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}
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